1. Field of the Invention
The invention relates to an electric machine that is supplied with air for cooling purposes. The air is heated during operation of the electric machine and is removed in the form of exhaust air. The electric machine has a fan wheel coupled to a rotor of the electric machine. The invention also relates to a motor vehicle with such an electric machine and to a method for operating an electric machine.
2. Description of the Related Art
U.S. Pat. No. 7,362,016 discloses an electric motor with a cooling means and suitable sensors. US Patent Application Pub. No. US 2007/0046111 A1 discloses an electric motor with a ventilation device. German laid-open application DE 31 09 621 A1 discloses a multi-phase A.C. motor with a rotational speed sensor consisting of a disk-shaped transmitter and a receiver. The disk-shaped transmitter is fastened to the hub.
It is the object of the invention to improve and/or to simplify the operation of an electric machine that is supplied with air for cooling purposes, where the air that is heated during operation of the electric machine and is removed in the form of exhaust air, and that has a fan wheel coupled to a rotor of the electric machine.